Preventing errors where there is no previous wav file.

owrx/audio/wav.py

@@ -85,36 +85,37 @@ class AudioWriter(object):
             file = self.wavefile
             self.wavefile = self.getWaveFile()
 
-        file.close()
-        tmp_dir = CoreConfig().get_temporary_directory()
+        if file is not None:
+            file.close()
+            tmp_dir = CoreConfig().get_temporary_directory()
+
+            for profile in self.profiles:
+                # create hardlinks for the individual profiles
+                filename = "{tmp_dir}/openwebrx-audiochopper-{pid}-{timestamp}.wav".format(
+                    tmp_dir=tmp_dir,
+                    pid=id(profile),
+                    timestamp=file.getTimestamp().strftime(profile.getFileTimestampFormat()),
+                )
+                try:
+                    os.link(file.getFileName(), filename)
+                except OSError:
+                    logger.exception("Error while linking job files")
+                    continue
+
+                job = self.chopper.createJob(profile, filename)
+                try:
+                    DecoderQueue.getSharedInstance().put(job)
+                except Full:
+                    logger.warning("decoding queue overflow; dropping one file")
+                    job.unlink()
 
-        for profile in self.profiles:
-            # create hardlinks for the individual profiles
-            filename = "{tmp_dir}/openwebrx-audiochopper-{pid}-{timestamp}.wav".format(
-                tmp_dir=tmp_dir,
-                pid=id(profile),
-                timestamp=file.getTimestamp().strftime(profile.getFileTimestampFormat()),
-            )
             try:
-                os.link(file.getFileName(), filename)
+                # our master can be deleted now, the profiles will delete their hardlinked copies after processing
+                file.unlink()
             except OSError:
-                logger.exception("Error while linking job files")
-                continue
+                logger.exception("Error while unlinking job files")
 
-            job = self.chopper.createJob(profile, filename)
-            try:
-                DecoderQueue.getSharedInstance().put(job)
-            except Full:
-                logger.warning("decoding queue overflow; dropping one file")
-                job.unlink()
-
-        try:
-            # our master can be deleted now, the profiles will delete their hardlinked copies after processing
-            file.unlink()
-        except OSError:
-            logger.exception("Error while unlinking job files")
-
-        self._scheduleNextSwitch()
+            self._scheduleNextSwitch()
 
     def start(self):
         self.wavefile = self.getWaveFile()